In the field of medical surgery, conventional processes involve making long incisions on the patient's body. For example, in a cardiac surgery of the coronary artery, the patient's chest is opened and the surgery is performed on the heart. In the present days, these are being replaced by Minimally Invasive Surgery (MIS). In MIS, instead of long incisions, small incisions are made for enabling an operating equipment to enter the patient's body and perform the surgery.
MIS is performed by using a robotic instrument assembly that typically includes straight, elongated shafts (hereinafter referred to as robotic arms), operational and/or monitoring equipment (hereinafter referred to as end effectors) and a console. The operational equipment is used to perform the medical procedures, such as scissors for cutting a tissue. Monitoring equipment, such as a camera or microphone, assist the operator in performing MIS. The console is used to control the motion of the robotic arm and the operational equipment. The inputs for controlling the components of the robotic instrument assembly are provided through a hand controller present in the console.
Further, the robotic instrument assembly includes a motor drive unit and a haptic feedback system. The motor drive unit is configured for inducing tensile forces in the drive element and articulating the movement of the robotic arms and the end effectors, thereby enabling the movement of the robotic arm in multiple degrees of freedom. The haptic force feedback is used by the operator during the surgical procedure to estimate the magnitude of the pressure that needs to be applied at the surgical site. The haptic feedback unit measures forces acting on the robotic arm and end effector assembly and uses these measured forces to produce the haptic force feedback characterized by counter forces and vibrations at the hand controller.
The value of the measured forces acting on the robotic arm and end effector assembly can be affected by several environmental and internal factors. These factors include tool-tissue engagement, tool tip vibrations, and vibrations arising from the mechanical assembly of the motor drive. Due to these factors, the measured forces include unwanted noise. In the present state of the art, the system does not include any arrangement to remove the noise generated due to environmental factors, thus leading to generation of an erroneous force feedback. Therefore, an operator is not able to correctly estimate the precise pressure required for performing the procedures. When the operator uses the incorrect estimate, the procedures may not be performed accurately, and may lead to injuries such as tissue damage.